Ribbon-feeding mechanism



Se t; 28, 1926.

. A. B. ELY

RIBBON FEEDING MECHANISM Filed April 9. 1923 2 Sheets-Sheet 1 IN VEN TOR.A 10125015.

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M in ATTORNEYS Sept. 23', 1926. A. B. ELY

RIB BON FEEDING MECHANISI Filed April 9'. 1923 2 Sheets-Sheet 2 INVENTORAla/150,15. E9

' ATTORNEY$ Patented Sept, 28, 1926.

UNITED- STATES earns PATENT OFFICE.

ALONZO B. ELY, OF GROTON, NEW YORK, ASSIGNOR TO CORONA TYPEWRI'IER COM-PANY, INQ, OF GRO'ION, -I\TEW YORK, A CORPORATION OF NEW YORK.

RIBBON-FEEDING MECHANISM;

Application filed April 9,

This invention relates to improvements in ribbon feeding mechanism fortypewriting machines. recording calculators, and the like, and has forits principal object to provide a simple and inexpensive mechanism forrotating the ribbon spools which is substantially noiseless in operationand positivein its feeding action. Other objects are to provide a pawland ratchet feed mechanism w adjnstable to compensate for inaccuraciesin manufacture of the parts. in which backlash is eliminated, and inwhich the parts are so constructed and arranged that the ribbon will bepositively fed a predetermined extent at each operation of the feedmechanism notwithstanding inaccurate formation or assembly of the partsof said pawl and ratchet mechanism, such as ecrentr icratchet wheels andbent or improper-. 1y aimed shafts for the ratchet wheels.

The improvements have been illustrated in connection with a' Coronatypewriting machine equipped with an automatic ribbon feeding andreversing mechanism constructed as shown in the application of Otto.Petermann filed October 21, 1922, Serial No. 596,062, but, while oneobject of the present invention is to provide a highly efficient andsubstantially noiseless ribbon feeding mechanism for said Coronamachine, it will be obvious that the improvements are not limitedin'their application to said machine.

In the accompanying drawings,

Figure 1 is a vertical longitudinal sectional view of a Coronatypewriting machine provided with the improved feed mechanism i Fig. 2 adetail view showing one of the feed pawls near the end of the rearwardmoven'ieut of'the rocking frame;

a plan view of the mechanism for rotating the right-hand spool;

Fig. 4 a perspective view of one of the feed pawls; Y

5 a front elevation of the parts shown in Fig. 3; and

Fig. 6 a side elevation of the parts shown in Fig. 3.

Referring to the parts by numerals, l designatesthe main or base framepart of the Corona machine; 2 designates the vertically shift-able postsslidably held in guide brackets 3 at opposite sides of the frame 1;

r f a designates the forwardly extending arms 1923. Serial No. 630,788.

'6 designates the folding arm s pivotally held by screws 37 at theirforward ends to the forward ends of barset and carrying the bed 7 forthe platen carriage 8 at their rear ends. Arms 6 are foldable' forwardlyto place bed 7, carriage 8 and platen 9 in inverted position over thekeyboard. Posts 2 are connected at their lower ends by a rod 10shiftable vertically by a pair of shift key levers (not shown) toelevate posts 2, arms 4 and 6, and the parts thereon to two clifferentcase-shift positions.

The printing key levers 11 are pivoted on fulcrum rods 12 in the frame 1and are connected by links 13 to type bars 1 1 mounted on pivot wire 15in a segment 16 secured to the rear wall of the main frame. Each keylever has a finger 17 underlying the transverse member of a universalbar 18 which is substantially U-shape in plan view and has-its side armspivoted on the rear fulcrunirod 12. The space bar 19 is supported onspacing levers 19 pivoted on a rod 20 in the frame 1 and engaging underthe universal bar at their rear ends. The key levers, spacing levers anduniversal bar are restored'to normal position after operation by returnsprings 21 connecting the same with a bracket 22 in frame 1.

'A. pair of upstanding levers 23, connected at their upper ends by across-bar 2 1, are pivoted intermediate their ends on screws 25 threadedin brackets 3. Said levers are rocked fore and aft of the machine bylinks 26'connecting the lower ends thereof with the universal bar 18,and said levers are provided with lugs 27 engaging in slots 28 in theside arms 29 of an upstanding sheet metal universal rocking frame. Thisframe is of substantially inverted U-shape, the side arms 29 beingconnected at their upper ends by an integral, flat cross-bar 30 andbeing pivoted at their lower ends on red 10. The frame swings fore andaft of the machine when levers 23 are rocked and moves vertically withrod 10 during case shifting. The cross-bar 30 is provided with means foractuating the ribbon vibrating mechanism of the Corona machine (notshown) and also carries a tappet 31 for actuating the escape mentdog-rocker of said machine (not shown).

The inked ribbon 38 is connected at its ends 45 rigidly held to bracketsl3.

in the usual manner to a pair of ribbon spools "i1, only one of thesespools being shown as the spools at both sides of the machine and therotating means therefor are constructed in the same manner. On eachfolding frame arm 6 a sheet metal bracket 43 is rigidly secured byscrews 44.. Spools 41 are held to rotate with sleeves 63 rotatably andslidably mounted on posts Worm gears 6% fixed on the lower ends ofsleeves 63 mesh with worms 52 fir-(ed on shafts 51 each journalled inears 48 and a9 on one of the brackets 43. Ratchet wheels 53, stampedfrom sheet metal stock, are fixed on the inner ends of the worm shafts51 to rotate with the shafts. An arm 54- extends forwardly from ear l8,said arm lying in a vertical plane and formed at its forward end with alaterally bent lug 56 disposed in a horizontal plane forward of and in aplane higher than the adjacent worm shaft 51. Ratchets 53 are spaced asubstantial distance inside of the ears 48. The cross-bar 30 of theuniversal rocking frame is formed at its ends with ears 35 lying in avertical plane Xtending fore and aft of the machine, said ears beinglocated inside of and to the rear of the ratchet wheels 53. The crossbaris also formed at its ends with outwardly extending stop lingers 30located under the ratchet wheels. Trip devices controlled by the ribbongovern the operation of suitable feed-reversing mechanism which movesone worm gear 64: into mesh with its associated worm 52 andsimultaneously moves the other worm gear 64. out of mesh with itsassociated worm 52. The foregoing parts are all constructed as shown anddescribed in said application of Otto Petermann above referred to, andthe improvements will be now described.

A one-piece, sheet metal feed-pawl is pivotally held against the outerface of each ear 35 on the rocking frame by means of a shouldered pivotscrew 91 which extends through an aperture 92 in the main body portionof the pawl intermediate the ends of the pawl. The main body part 90 ofthe pawl is flat and lies in a vertical plane eat-ending parallel withand inside of the inner face of the adjacent ratchet wheel 53. Part 90of the pawl is formed with a horizontal slot 93 extending rearward fromthe forward end of the pawl, and stop finger 3O on the rocking frameextends through this slot which is substantially wider than thethickness ofthe stop finger. The up )er part of the slotted forwardportion of the pawl body is formed with an integral, laterally bent lug94f which extends upwardly above the upper edge of. the pawl body and isbeveled along its upper edge to form a 9. adapted s ssees e e h neonesaratchet 53 below the axis of said ratchet. Lug 94 is preferably made twoor three times as wide as the thickness of the ratchet wheel so itsbroad nose part 95 will cooperate with the ratchet notwithstandinginaccuracies in manufacture of the parts. Said lug is also slottedhorizontally for about half its width at 96 whereby nose part 95 may bepermanently bent up and down. Lug 9a is permanently bendable fore andaft of the machine. It will be thus seen that the nose part of the pawlmay be adjusted at various angles as may be required by imperfectmanufacture or assembly of the several parts of the pawl and ratchetfeed mechanism. 1

The rear portion ofthe pawl body '90 is offset upwardly relatively tothe forward portion so that substantially all of the ma terial of whichsaid rear portion is formed is located above the horizontal plane of thepivotal. axis of the pawl. This rear or tail piece of the aawl is rolledor folded laterally upon itself as shown at- 97 to form acompartweighted tail portion for the pawl. It will be noted that the weightedtail piece is located entirely at the rear of the pivotal axis of thepawl and entirely, or substantially entirely, in a plane above thehorizontal plane of the pivotal axis of the pawl. t will be obvious,therefore, that on the back stroke of the pawl, when a printing key orthe space bar is depressed, the nose 95 will ride very lightly andsubstantially without noise over the teeth of ratchet 53 owing to thearrangement of the weighted tail of the pawl, while on the forwardstroke of the pawl the weighted tail will insure immediate and continuedengagement of nose 95 between the. teeth of the ratchet as the rockingframe 293O begins its return or forward movement. Positive feeding ofthe ribbon the desired extent at each key operation is thus insured evenduring very rapid operation of the machine.

To prevent back-lash of the ratchet wheels 53 during the backward strokeof the feed pawls 90, a noiseless detent or brake device 98 is providedfor each spool rotating means. These detents comprise flatspringsseoured by screws 99 at their forward ends on top of lugs 56 onarms 54 of brackets d3, said springs being bent downward at 100 near therear edge of lugs 56 andpressing firmly down under tension on the wormshafts 5.1 between ratchet wheels 53 and ears L8. Springs 98 thus serveto frictionally hold shafts 51 and ratchets 53against reverse rotationand accomplish this result in a silent manner.

Fingers 30.- l'imit the rocking of. the feed pawls in both directionsand prevent weights 9? from moving to a point where they will n tautomatically more. the noses. at the palWIs into Operative engagementwith the cii ratchet wheels when the machine is placed in an uprightposition and unfolded, as will be obvious from an inspection of Figs. 1and 2,

hat I claim is'f w 1. In a ribbon feeding mechanism, the combination ofa drive shaft, a ribbon spool driven from said shaft, a ratchet wheel onsaid shaft, a broad flat resilient detent member frictionally engagingsaid shaft adjacent one end of said member, means rigidly supportingsaid member at its other end, a vibrating pawl carrier, means forvibrating said carrier, and a one-piece sheet metal pawl pivotally heldto said carrier having a nose engaging the ratchet Wheel and a tailportion folded upon itself to form a counterweight.

2 In a ribbon feeding mechanism, the combination of a drive shaft, aribbon spool driven from said shaft, a ratchet wheel on said shaft, abroad flat resilient detent member frictionally engaging said shaft adjacent one end of said member, means rigidly supporting said member at itsother end, a vibrating pawl carrier, means for vibrating said carrier,and a one-piece sheet metal pawl pivotally held to said carrier having anose engaging the ratchet wheel and a tail portion folded upon itselfto, form a counterweight, said tail portion being located substantiallyentirely at that side of the plane of movement of the pivotal axis ofthe pawl nearest the ratchet wheel.

3. In a ribbon feeding mechanism, the combination of a drive shaft, aribbon spool driven from said shaft, a ratchet Wheel on said shaft, abroad fiat resilient detent member frictionally engaging said shaftadjacent one end of said member, means rigidly supporting said member atits other end, a vibrating pawl carrier, means for vibrating saidcarrier, and a one-piece sheet metal pawl pivotally held to said carrierhaving a nose engaging the ratchet wheel and a tail portion folded uponitself to form a counterweight, said tail portion being locatedsubstantially entirely at that side of the plane of movement of thepivotal axis of the pawl nearest the ratchet wheel and said nose beingsubstantially wider than the thickness of the ratchet wheel.

4. In a ribbon feed mechanism, the combination of a rotatably mountedspool-driving ratchet wheel, means supporting said ratchet wheel torotate about a horizontal axis, a sheet metal feed pawl having a noseco-operating with the teeth of the ratchet wheel, means supporting thepawl for pivotal movement about an axis parallel with the axis of theratchet wheel, and key actuated means for moving the pivotal support ofthe pawl back and forth transversely of the axes of the pawl and ratchetwheel, the body ortion of the pawl being disposed vertically edgewiseand having the major portion of its mass located above and at theopposite side of the axis of the pawl from that at which the nose of thepawl is located.

5. In a ribbin feed mechanism, the combination of a horizontallydisposed spool driving shaft, a ratchet wheel fixed on said shaft, apivoted feed pawl having an up turned nose at on side of its pivotalaxis for engaging the ratchet wheel, means movable transversely of thespool-driving shaft for pivotally supporting the pawl on an axisparallel with and below the spool-driving shaft, and a counterweightcarried by said pawl at the opposite side of its pivotal axis from thenose of the pawl, said counterweight being located substantiallyentirely above the plane of movement of the pivotal axis of the pawl.

6. In a ribbon feed mechanism, the combination of a horizontallydisposed spooldriving shaft, a ratchet wheel fixed on said shaft, apivoted feed pawl having an upturned nose at one side of its pivotalaxis for engaging the ratchet wheel, means movable transversely of thespool-driving shaft for pivotally supporting the pawl on an'axisparallel with and below the spool-driving shaft, a counterweight carriedby said pawl at the opposite side of its pivotal axis from the nose ofthe pawl, said counterweight being located substantially entirely abovethe plane of movement of the pivotal axis of the pawl, and a springdetent frictionally engaging the spool-driving shaft under tension.

7. In a ribbon feed mechanism, the combination of a horizontallydisposed spooldriving shaft, a ratchet wheel fixed on said shaft, apivoted feed pawl having an up turned nose at one side of its pivotalaxis for engaging the ratchet wheel, means movable transversely of thespool-driving shaft for pivotally supporting the pawl on an axisparallel with and below the spooldriving shaft, a counterweight carriedby said pawl at the opposite side of its pivotal axis from the nose ofthe pawl, said counterweight being located substantially entirely abovethe plane of movement of the pivotal axis of the pawl, and means forrestraining swinging movements of the pawl about its pivot in bothdirections substantially beyond that necessary for engagement anddisengage ment of the pawl nose with the teeth of the ratchet wheel.

8. A silent ribbon feed mechanism, comprising a spool driving ratchetwheel, means supporting said wheel to rotate about a horizontal axis, afeed pawl having a nose and a counterweighted tail portion, a vibratorypawl carrier, means plvotally supporting said pawl on the carrier at apoint intermediate said nose and tail portion of the pawl to turn abouta horizontal axis, and

lit)

j nose of the pawl back and forth between i toothed spaces of theratchet wheel located below the liori zontal plane of the sis ofretation of said wheel.

9. A silent ribbon feed mechanism, comprising a spool driving ratchetwheel, means supporting'said wheel to rotate about a horizontal axis; afeed pawl having a nose and a; counterweighted tail portion, a vibratorypawl carrier, means pivotally supporting said pawl on the carrier at apoint intermediate said nose and tail portion of the pawl to turn abouta horizontal axis, means for vibrating the carrier to shift the nose ofthe pawl back and forth between tooth spaces of the ratchet wheellocated below the horizontal plane of the axis of rotation of saidwheel, and a friction brake means for resisting back-lash of the ratchetwheel.

10. In a typewriting maol ine having a ribbon spool and a universal bar,the combi nation of a spool. driving ratchet wheel, a shaft supportingsaid wheel to rotate about a horizontal axis extending transversely ofthe machine, a pawl carrier, means supporting said carrier to swingabout an axis extending transversely of the machine at a lower levelthan the wheel sh aft, a feed pawl having an'ose and a counterweightedtail portion, means pivotally supporting said pawl at a point betweensaid nose and tail portion thereof on the pawl carrier above the pivotalaxis of the carrier, and means for rocking said carrier from theuniversal bar to vibrate the nose of the pawl between tooth spaces ofsaid wheel located below the horizontal plane of the axis of the wheel.

11. In a typewriting machine, a silent ribbon. feedingmeans comprising auniversal bar, a rocking member operable by the universal bar andsupported to vibrate about a horizontal axis, a horizontally disposedrib bon spool drive shaft, a ratchet wheel fixed on said shaft, a pawlpivoted'on said rocker member to swing about a horizontal axis, saidpawl having a nose at one side of its pivot extending under the ratchetwheel and a weighted tail portion at the opposite side of its pivotlocated substantially entirely above the horizontal plane of the pivotalaxis of the pawl, and a friction detent en gaging said drive shaft.

12. In a typewriting machine, the combination with a ribbon spool and ahorizontal ly disposed shaft connected to drive said spool, of a ratchetwheel fixed on said shaft, a hey-operated member movable transversely ofthe shaft, and a sheet metal pawl pivotally held to said member andextending transversely of the shaftnnder the ratchet wheel, said pawlhaving a laterally bent nose portion at one end beveled along its upperedge for engagement with the teeth of the ratchet wheel, said noseportion being substantially wider than the thickness of the ratchetwheel and provided with a slot ex tending; horizontally from one sideedge thereof.

13. In a typewriting machine, the combi nation with a ribbon spool and ahorizontally disposed shaft connected to drive said spool, of a ratchetwheel fixed on said shaft, a key-operated member movable transverse lyof the shaft, and a sheet metal pawl pivotally held to said member andextending transversely of the shaft under the ratchet wheel, said pawlhaving a laterally bent nose portion at one end beveled along; its upperedge for engagement with the teeth of the ratchet wheel, said noseportion being substantially wider than the thickness of the ratchetwheel and provi led with a slot extending horizontally from one sideedge thereof,,and said pawl having an integral tail portion folded uponitself with the major portion thereof located above the horizontal planeof the pivot of the pawl.

14:. In a typewriting machine, the combination with a ribbon spool and ahorizontally disposed shaft connected to drive said spool, of a ratchetwheel fixed on said shaft, alrey-operated member movable transverse lyof the shaft, a pawl extending transversely of the shaft under theratchet wheel and formed at one end with an upturned nose engaging theratchet wheel, means pivotally holding the pawl intermediate its ends tosaid key-operated member to swing up and down, a weight carried by theother end of the pawl having its major portion located above thehorizontal plane of the pawl pivot, said pawl being provided with a slotat one side of its pivot, and afixed stop carried by the key-operatedmember engaged in said slot for limiting the swinging movements of thepawl about its pivot.

In testimony whereof I hereunto aflix my signature.

ALONZO B. ELY,

